1218 Instrument Testing & Calibration Procedure Ntgfdp.doc

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CONTENTS 1.0 SCOPE

3

2.0 APPLICATION

3

3.0 OBJECTIVE

3

4.0 RESPONSIBILITIES

3

5.0 DEFINITIONS

4

6.0 PROCEDURES

5

6.1 CALIBRATION OF PRESSURE GAUGE

5

6.2 PRESSURE TRANSMITTER - PNEUMATIC/ELECTRONIC

7

6.3 PRESSURE SWITCH - PNEUMATIC/ELECTRONIC

9

6.4 DIFFERENTIAL PRESSURE GAUGE

10

6.5 DIFFERENTIAL PRESSURE TRANSMITTER - PNEUMATIC/ELECTRONIC

11

6.6

DIFFERENTIAL PRESSURE SWITCH

13

6.7

TEMPERATURE INDICATORS

14

6.8

TEMPERATURE TRANSMITTER (FILLED SYSTEM TYPE)

15

6.9

TEMPERATURE TRANSMITTER (THERMOCOUPLE TYPE)

18

6.10 TEMPERATURE SWITCH

20

6.11

22

RESISTANCE TEMPERATURE DETECTOR

6.12 THERMOCOUPLE

23

6.13 TEMPERATURE TRANSMITTER (RTD TYPE)

24

6.14 LEVEL TRANSMITTER - INTERNAL DISPLACER TYPE P/E

26

6.15 LEVEL TRANSMITTER - EXTERNAL DISPLACER TYPE P/E

30

6.16 FLOAT OPERATED LEVEL SWITCH

33

6.17 SOLENOID VALVES

35

6.18 CONTROL VALVES

35

6.19 BALL VALVES

39

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6.20 CYLINDER VALVE

41

6.21 SAFETY RELIEF VALVE

43

6.22 RELAY, BOOSTER & CONVERTER

46

6.23 PNEUMATIC CONTROL CIRCUIT PRESS TEST

2.0

Page 2 of 55

47

6.24 ELECTRONIC RECORDER

48

6.25 PNEUMATIC RECORDER

49

6.26 PRESSURE & TEMPERATURE RECORDERS

50

6.27 ORIFICE PLATE

54

6.28 FLOWMETER

54

6.29 FIRE & GAS SYSTEM

54

1.0

SCOPE: This document identifies the various Work Method Statements and / or individual Testing Procedures that are generally foreseen to be used during the performance of the Instrument calibration works.

2.0 APPLICATION: The work Method Statements/Procedures and the associated Check sheet(s), shall be used, as may be deemed necessary during the performance of Instrument Testing & Calibration activities related to the project. 3.0 OBJECTIVES: These Work Method Statement/Procedure and Check sheets provide a reference guideline based on good Engineering practice, for performance of the relevant works. However, it is explicitly understood that these procedures may be modified, if deemed necessary, to suit the individual requirements of the Project in order to comply with the requirements of the Contract Documents. 4.0 RESPONSIBILITIES: 4.1

Lead E & I Engineer assigned to the project shall be responsible for Supervising and Coordinating the implementation of various Procedures and Check sheets, with due considerations being given to the Project specification and Contract requirements. He shall be also responsible for ascertaining the exact requirements of Materials and Consumables on the Project.

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4.2

The instrument site Workshop Supervisor under the guidance of Lead E & I Engineer shall be responsible for conforming to and complying with, the applicable Calibration and Certification requirements of the Project Specifications during execution of the Contract works.

4.3

The E&I Site Engineer shall also be responsible for ensuring that proper check sheets which may be applicable for the Project are made available for recording the results.

4.4

Inspector in conjunction with the Client Representative shall be responsible for checking and witnessing the performance of the E&I works and completion of the various Inspection/Test Record Check sheets to meet the documentation requirements of the Project. The E&I Inspector shall also be responsible for identifying any nonconformance, observed during the execution of his responsibilities.

5.0 DEFINITIONS: 5.1

Inspection Activities such as measuring, examining, testing, gauging one or more characteristics of a product or service and comparing these with specified requirements to determine conformity.

5.2

Testing The determination or verification of the capability of an item to meet specified requirements by sub testing the item to a set of physical, chemical, environmental or operating conditions.

5.3

Calibration The process of comparing the output of any given Instrument/Equipment against the output of a Standard/ Reference Instrument, when the same input is applied to both Instruments.

5.4

Pre-commissioning Pre-commissioning activities are non-operating adjustments and Calibration and cold alignment checks, generally carried out to ensure functionality of the item to perform under specified conditions.

5.5

Ready for Commissioning It is the state of condition of the Plant/Equipment or System, which has been

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erected in accordance with drawings, specifications instruction and applicable Codes and Regulation and after all Pre-commissioning checks "under simulated conditions" have been carried to the extent necessary for operating and Commissioning the Plant/ Equipment or System. 5.6

Commissioning Commissioning activities are associated with carrying out operational checks and adjustments on individual equipment items and/or systems/subsystem to facilitate plant start-up and operation of the facilities.

5.7

Quality The totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs.

5.8

Quality Assurance

5.9

All those planned and systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements for quality. Quality Control The operational techniques and activities that are used to fulfil requirements for quality.

5.10

Preservation The process for maintaining the physical condition and characteristics of an instrument/equipment item, from the time of receipt until its handing over upon completion of the works, so that it can perform within the established design parameters of its intended duty.

5.11

Non-Conformance The non-fulfillment of specified requirements.

5.12

Concession, Waiver Written authorization to use or release a quantity of material, components or stores already produced but which do not conform to the specified requirements.

6.0

PROCEDURES:

6.1

CALIBRATION OF PRESSURE GAUGE: a.

For calibration either Manometric balance or Dead Weight Testers can be utilized. Make connections as shown in Fig.1A & 1B in page no. 6.

b. Pressure gauges shall be ZERO set, if ZERO OFFSET is less than 10% of full scale. c. Pressure gauge shall be inspected for proper range and for evidence of damage.

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d. Apply pressure gradually in steps of 0%, 25%, 50%, 75% and 100% of the gauge range using pre-calibrated/certified equipment viz. Dead Weight Tester, Manometer etc. Measure the reading on gauges for accuracy and record it on the suitable test forms. e.

Reduce the pressure gradually in steps of 100%, 75%, 50%, 25% and 0% and observe the reading and record the same.

f. In case of large numbers of pressure gauges to be calibrated, then pressure comparator can be used with prior approval of Client.Standard pressure gauges, thoroughly checked/calibrated using Dead Weight Tester can be used as reference in this case. The standard gauge need to be recalibrated / tested against Dead Weight Tester after every 25 gauges comparison. g.

Pressure gauges that do not function properly during initial operations shall be replaced or repaired PRESSURE GUAGE

DEAD WEIGHT TESTER FIG. - 1A

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PRESSURE GAUGE

MANOMETER WATER/MERCURY

CALIBRATING AIR SUPPLY

FIG. - 1B TEST CIRCUIT FOR CALIBRATION OF PRESSURE GAUGE

6.2

PRESSURE TRANSMITTER – PNEUMATIC / ELECTRONIC: a.

Obtain the required actuating pressure by means of a variable Hydraulic or pneumatic supply or by means of dead weight tester.

b.

Calibrating Test Equipment shall be provided which can simulate analogue input signals over the full transmitter range. Using standard test equipment and making connections according to figure 2A and 2B shown in page no. 8 proceed with Testing of the Transmitter.

c.

The actuating pressure for the test shall be connected to the correct instrument process connection via a tee piece. The leg of the tee connected to the actuating pressure shall have a lock off valve and a vent valve. The other leg of the tee shall be connected to a suitable test gauge.

d.

At zero input signal/the transmitter pressure, adjust zero adjustment screw so that the out pressure gauge reads 3 psi or 0.2 Kg/Cm2.

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e.

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With lock off valve open and vent valve closed gradually increase the pressure on the Transmitter input. Close lock off valve and check system for leaks. [Shall be applied intermittently increasing from 0% - 100% and reducing from 100% - 0% in steps of 25% as detailed on the calibration sheet. -

Open vent valve and recheck zero.

f.

The % error calculated from the results above shall not exceed the manufacturers stated limits.

g.

Transmitters with indicating scales shall where necessary have their indicators also calibrated during test.

h.

After testing, all spare entries and/or openings shall be appropriately closed and/or blanked off to prove subsequent ingress of moisture or dirt.

STD PRESSURE GAUGE PRESSURE GAUGE

STANDARD GAUGE PRESSURE

LOCK OF VALVE

TRANSIMITTER

COMPARATOR FIG. - 2A

DRAIN

REGULATED

VALVE

AIR SUPPLY

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ELECTRONIC STANDARD GAUGE

DIGITAL MILLI AMMETER mA PRESSURE TRANSIMITTER

DC

COMPARATOR

FIG. -2B

6.3

PRESSURE SWITCH – PNEUMATIC / ELECTRONIC: a.

Calibration test equipment shall be provided which can simulate analogue input signals over the specified switch range. During calibration, the generated input signal value shall be visually displayed using standard test equipment.

b.

Make connections as per figures shown below 3A & 3B in page no.9 & 10 respectively.

c.

An electrical continuity meter shall be connected across the switch electrical terminals to display switch continuity status.

d.

The signal input shall be increased to a value where the switch contacts change status. viz. the threshold position. This value of pressure at threshold position shall be recorded.

e.

The signal input shall then be reduced to the pre-test condition.

f.

If necessary the set point and switch differential (if not of fixed type) shall be adjusted to specifications as given in the engineering data sheet.

g.

After calibration, pressure switches shall not be subjected to sudden

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movements, acceleration or shock and shall be protected from moisture, dirt and large temperature variations. h.

After testing, all connections and entries shall be sealed to prevent the subsequent ingress of moisture or dirt. STANDARD GAUGE PRESSURE SWITCH CONTINUITY TESTER

COMPARATOR FIG. - 3A

PRESSURE SWITCH CONTINUITY TESTER

MANOMETER WATER / MERCURY

CALIBRATING AIR SUPPLY

FIG. - 3B TEST CIRUIT FOR CALIBRATION OF PRESSURE SWITCH

6.4

DIFFERNTIAL PRESSURE GAUGE:

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a. For differential pressure gauge pressure shall be applied to "HP" Port only with "LP" Port open to atmosphere and the equalizing valve closed. b.

Make connections according to figure 4 shown in page no.11.

c.

Calibrating test equipment shall be provided which can simulate analogue input signals over the full pressure gauge range. During calibration, the generated input signal value shall be visually displayed using standard test equipment. Pressure gauge input shall be applied incrementally from 0%---->100%---->0% in the steps as detailed on the calibration sheet or 25% increments.

d.

The pressure shall be applied by using a Dead Weight Tester. Water pump or by the application of a regulated pneumatic, air supply. The selection of testing equipment shall depend upon the pressure gauge type and range. Vacuum measuring pressure gauge shall be connected to a vacuum pumping system and Hg (Mercury) manometer indicator system.

e.

The % error calculated from the results of the above test shall not exceed the manufacturer’s limits.

STANDARD GAUGE DIFFERENTIA L PRESSURE GA UGE

LP PORT

HP PORT

CONTINUITY TESTER

OPEN TO ATMOSPHERE

COMPARATOR

FIG. - 4

TEST CIRCUIT FOR CALIBRATION OF DIFFERENTIAL PRESSURE GAUGE

6.5

DIFFERENTIAL PRESSURE TRANSMITTER – PNEUMATIC / ELECTRONIC: a.

Make connections according to figures 5A & 5B shown in page no.12 & 13 respectively.

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b.

The required actuating pressure shall be obtained by means of variable air supply or dead weight tester.

c.

Connect the output as follows: (a) (b)

For electronic DPT For Pneumatic DPT

: :

To a suitable test meter. To a manometer or pneumatic calibrator.

,,,,,

,

6.6

d.

Pressure shall be applied to the process impulse port using a Dead Weight Tester water pump or by the application of a regulated pneumatic air supply. The selection of testing equipment shall depend upon the transmitter type and range. Vacuum measuring transmitters shall be connected to a vacuum pumping system and mercury manometer indicator system.

e.

Static ‘Pressure Test’ of Differential pressure transmitter static should be carried out by connecting the HP and LP sides of the transmitter together and applying maximum working pressure. At the zero differential pressure adjust zero adjustment screw to an output of 50% of the transmitter. When applied maximum working pressure deviation in out reading permitted should be within the tolerance limits specified by the manufacturer.

f.

At Zero differential pressure adjust ZERO adjustment screw so that the standard pressure gauge reads 0.2 Kg/CM2/3 PSI.

g.

With lock valve open and vent valve closed apply an actuating pressure of approximate full range. Close lock off valve and check system for leaks. When no fall in pressure is observed i.e. indicates no leaks. Open vent valve and recheck Zero. Vent low pressure port of DPT to atmosphere.

h.

Apply actuating pressures equivalent to 0. 25, 50, 75 & 100% of instrument range. Record corresponding output readings. Apply 110% signal as a check for hysteresis.

i.

Using vent valve reduce actuating pressures equivalent to 100, 75, 50, 25 and 0% of instrument range Record corresponding output readings.

j.

The % error calculated from the results of the above test shall not exceed the manufacturers stated limits

k.

Transmitters with indicating scales shall where necessary have their indicators calibrated during these tests.

DIFFERENTIAL PRESSURE SWITCH: a.

Make connections as shown in the figure 6 shown in page no. 14 of 66.

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b.

An Electrical continuity meter shall be connected across the switch electrical terminals to display switch continuity status.

c.

For differential pressure switches, pressure shall be applied to the "HP" port only with the "LP" port open to atmosphere and the equalizing valve closed, provided switch is calibrated along with manifold fitted.

d.

Pressure shall be applied to the process impulse port, using a Dead Weight Tester, water pump or by the application of regulated pneumatic air supply. The selection of testing equipment shall depend upon the switch type and process range.

e.

The signal input shall be increased to a value where the switch contacts change status viz. the threshold position. The value of pressure at threshold position shall be recorded.

f.

The signal input shall be reduced to the pre-test condition.

g.

If necessary the set point shall be adjusted to specifications as given in the engineering data sheet.

h.

After calibration switches shall not be subjected to sudden movements, acceleration or shock and shall be protected from moisture, dirt and large temperature variations.

i.

After testing, all connections and entries shall be sealed to prevent the subsequent ingress of moisture

STANDARD GAUGE DIFFERENTIAL PRESSURE SWITCH

LP PORT CONTINUITY TESTER

OPEN TO ATMOSPHERE

COMPARATOR

FIGURE : 6

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TEMPERATURE INDICATORS: a.

Thermometers shall be inspected for proper ranges and evidence of damage.

b.

Make connection as shown in Fig. 7 shown in page no.15.

c.

Immerse the bulb in the standard/certified Temperature Calibrator.

d.

Thermometers shall be ZERO set of ZERO OFFSET is less that 10% of full range.

e.

Simulate analogue input signals over the full range of the indicator type instrumentation under test. During calibration, the generated analogue input signal value shall be usually displayed by using standard test equipment. The input and impulse signal shall be applied incrementally through 0% - 100% - 0% as detailed in the calibration sheet.

f.

When the input signal is incrementally applied, comparison shall be made between the signal input as displayed the standard test equipment monitor and the signal input as displayed by the indicator under test. If necessary, the zero and span adjustments of the indicator under test shall be altered to minimize or remove discrepancies between the calibration standard display and the indicator under test.

g.

Thermometers that do not function properly during initial operations shall be replaced or repaired with prior approval of the Client.

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TEMPERATURE INDICATOR STANDARD

W/O THERMOWELL

THERMOMETER

WATER OR SILICON OIL

HEAT SOURCE

TEMPERATURE BATH FIG. - 7

TEST CIRCUIT FOR CALIBRATION OF TEMPERATURE INDICATOR

6.8

TEMPERATURE TRANSMITTERS (FILLED SYSTEM TYPE): a.

According to the type of transmitter make connections as shown in figures 8A and 8B shown in page no. 16 and 17 respectively.

b.

Immerse bulb in an oil bath fitted with an NPL or equivalent certified transmitter.

c.

Connect the output as follows: (a) (b)

d.

For electronic transmitter For pneumatic transmitter

: :

to a suitable test meter. to a pneumatic calibrator.

Raise both temperature to 50 and 100% of instrument range. Record corresponding output readings. The % error calculated from the results of the above tests shall not exceed the manufacturers stated limits.

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TEMPERATURE TRANSMITTERS (THERMOCOUPLE TYPE): (CURRENT TO PNEUMATIC AND PNEUMATIC TO CURRENT CONVERTORS FOR TRANSMISSION OF TEMPERATURE) a.

After checking the instrument connects a suitable pneumatic or electrical supply

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according to a figure 9A and 9B shown in page no. 19. b.

Connect the output as follows: (a) (b)

For Electrical Transmitter For pneumatic Transmitter -

to a suitable test meter. to a manometer or pneumatic calibrator.

c.

Convert the ambient temperature to equivalent millivolt using an approved conversion table.

d.

Transmitter shall be calibrated along with the Thermocouple by using suitable Equipment that is capable of producing a regulated temperature source.

e.

The calibration equipment shall be selected to provide a temperature variation over the full temperature transmitter process range.

f.

The transmitter shall be calibrated using equipment that is capable of producing a regulated temperature source. The transmitter temperature detection probe shall be inserted into the calibrating equipment in close proximity to the reference temperature probe. The transmitter out put is compared to the display as yielded by the reference temperature probe indication.

g.

When the heat source temperature is altered incrementally, time shall be allowed for the temperature to stabilize before the reference temperature is taken for calibration purpose.

h.

Similar analogue input signals over the full range of the indicator type instrumentation under test. During calibration, the generated analogue input signal value shall be usually displayed using standard test equipment. The input and impulse signal shall be applied incrementally through 0% - 100% - 200% as detailed on the calibration sheet.

i.

When the input signal is incrementally applied comparison shall be made between the signal input as displayed by the standard test equipment monitor, and the signal input as displayed by the indicator under test. If necessary, the zero and span adjustments of the indicator under test shall be altered to minimize or remove discrepancies between the calibration standard display and the indicator under test.

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STD: PRESSURE GAUGE PRECISION VOLTMETER PRESSURE GAUGE TEMPERATURE

input DC SOURCE

TRANSMITTER

OUT PUT

V REGULATED AIR SUPPLY

POTENTIO METER FIG.-9A

ELECTRONIC

PRECISION VOLTMETER

MILLI AMMETER

TEMPERATURE

input DC SOURCE

TRANSMITTER

mA OUT PUT

V

POTENTIO METER FIG.-9B

TEST CIRCUIT FOR CALIBRATION OF TEMPERATURE TRANSMITTER (THERMOCOUPLE)

6.10

TEMPERATURE SWITCH:

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a.

The calibration equipment shall be selected to provide a temperature variation over the full temperature switch process change.

b.

Make the connections to the switch according to figure 10A & 10B shown in page no. 21.

c.

An electrical continuity meter shall be connected across the switch electrical terminals to display switch continuity status.

d. Switch shall be calibrated by using equipment that is capable of producing a regulated temperature source. The temperature detection probe of the switch shall be inserted into the calibrating equipment in close proximity to the reference temperature probe. e. This voltage or resistance value whichever has been applied shall be converted to temperature and recorded with the help of conversion charts. f. The signal input shall be increased to a value where the switch contacts change state viz. the threshold position. The value of voltage or resistance at threshold position shall be recorded. g. This value of voltage or resistance shall be converted to temperature to obtain the point where switch changes status. h.

The signal input shall be reduced to pre-test condition.

i.

If necessary the set point shall be adjusted to specifications as per engineering data sheet.

j.

6.11

After testing all connections and entries shall be sealed to prevent the subsequent ingress of moisture and dirt. The switch shall not be subjected to large temperature variations thereafter.

RESISTANCE TEMPERATURE DETECTOR: a.

The calibration equipment shall be selected to provide a temperature variation over the full temperature sensor process range.

b.

Connections shall be made as shown in Fig.11 shown in page no.22.

c.

The RTD shall be calibrated using equipment that is capable of producing a regulated temperature source. The RTD output is compared to the display as yielded by the reference temperature probe indication.

d.

With the heat source, the temperature is altered incrementally. Time shall be

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allowed for the temperature to stabilize before the reference temperature is taken for calibration purpose. e.

Simulate analogue input signals over the full range of the RTD sensor under test. During calibration the generated analogue input signal valve shall be visually displayed using standard test equipment. The input signal shall be applied incrementally through 0% - 100% - 0% as detailed on the calibration sheet.

f.

When the input signal is incrementally applied comparison shall be made between the signal input as displayed by the standard test equipment monitor and the signal input as displayed by the indicator under test.

g.

The percentage error between the measured and converted valves shall not be beyond the manufacturers stated limits.

MULTIMETER

STANDARD

OUT PUT WHERE IS

THERMOMETER

CHANGE IN RESISTANCE

THERMO COUPLE SENSOR IN THERMOWELL WATER OR SILICON OIL

HEAT SOURCE

TEMPERATURE BATH

FIG. - 11

TEST CIRCUIT FOR CALIBRATION OF TEMPERATURE DETECTOR (R.T.D.)

6.12

THERMOCOUPLE: a.

The calibration equipment shall be selected to provide a temperature variation over the full temperature sensor process range.

b.

Connection shall be made as shown in Figure 12 shown in page no. 24.

c.

When the heat source temperature is altered incrementally, time shall be allowed for the temperature to stabilize before the reference temperature is taken for calibration purpose.

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d.

The thermocouple shall be calibrated using equipment that is capable of producing a regulated temperature source. The thermocouple output is compared to the display as yielded by the reference temperature probe indication.

f.

Simulate analogue input signals over the full range of the thermocouple under test. During calibration, the generated analogue input signal value shall be usually displayed using standard test equipment. The input signal shall be applied incrementally through 0% - 100% - 0% as detailed on the calibration sheet.

g.

When the input signal is incrementally applied comparison shall be made between the signal input as displayed by the standard test equipment monitor and the signal input as displayed, by the indicator under test.

h.

The percentage error between the measured and converted values shall not be beyond the manufacturers stated limits.

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MULTI METER

STD THERMO METER

RESISTANCE MEASSUREMENT

SENSOR W/O THERMOWELL

HEATING SOURCE TEMPERATURE BATH

FIG. - 12

TEST CIRCUIT FOR CALIBRATION OF TEMP. DETECTOR (THERMOCOUPLE)

6.13

TEMPERATURE TRANSMITTER (RTD TYPE): (CURRENT TO PNEUMATIC OR PNEUMATIC TO CURRENT CONVERTORS) a.

Calibrating test equipment shall be provided which can simulate analogue input signals over the full transmitter range. Usually displayed using standard test equipment.

b.

Connect a precision decade resistance box to the instrument input terminals.

c.

After checking the relevant instrument against its specification connects a suitable air/electrical supply according to figure 13A and 13B shown in page no. 25.

d.

Connect the output as follows: (a)

For Electronic transmitter

-

to a suitable test meter.

(b)

For Pneumatic transmitter

-

to a manometer or pneumatic calibrator.

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e. Transmitter input shall be applied incrementally from 0% - 100% - 0% in steps as detailed on the calibration sheet. f. When the input signal is incrementally applied comparison shall be made between the signal input as displayed by the standard test equipment monitor and the output as displayed by the Transmitter under test. If necessary the zero and span adjustments of the transmitter under test shall be altered to minimize or remove discrepancies between the calibration standard display and the transmitter under test. g. The percentage error calculated from the results of above tests shall not exceed the manufacturer stated limits.

ELECTRONIC

MILLI AMMETER mA TEMPERATURE TRANSMITTER OUT PUT INPUT

DECADE RESISTANCE BOX

FIG. - 13A

DC SOURCE

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STD: PRESSURE GAUGE

PRESSURE GAUGE TEMPERATURE TRANSMITTER VARIABLE AIR SUPPLY

DECADE RESISTANCE BOX

FIG. - 13B TEST CIRCUIT FOR CALIBRATION OF TEMP. TRANSMITTER (RTD)

6.14

LEVEL TRANSMITTER – INTERNAL DISPLACER TYPE – PNEUMATIC / ELECTRONIC: a.

Fabricate a suitable test rig to enable the float to be operated by raising and lowering the water level. Connect a water supply to the test rig via a tee piece. The leg of the tee connected to the water supply shall have a lock off valve and drain valve fitted. The other leg of the tee piece shall be connected to a glass or plastic water column secured to the chamber. A common datum line should be marked on the tube at mid range on the chamber.

b.

The transmitter shall be calibrated using water as process fluid if the transmitter does not have a specific gravity compensation then calibrated output must compensate for disparity between duty specific gravity and specific gravity of water (1.0). If transmitter has a specific gravity the adjustment, the adjustment shall be set at 1.0 for duration of calibration. When the calibration has been completed, the specific gravity adjustment can be set to the process specific gravity as specified on the Engineering Data Sheet.

c.

If the transmitter is pneumatic, then a regulated 20 psig air supply shall be connected to the input port, and standard pressure test gauge connected to the output port shown in figure 16A page no. 28.

d.

If the transmitter is electronic, then the remote mounted receiver, either level indicator or level indicator controller, shall be energized at a normal supply voltage, and a milliammeter connected in series with the transmitter output. The meter shall be capable of reading a current variation of 4 - 20 mA DC as shown in figure 16B page no. 29.

e.

With lock off valve open and drain valve closed raise water level to 0, 25, 50, 75

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and 100% of instrument range as indicated on graduated water column. Record corresponding output readings. Raise the water level to 110% and check against hysteresis. f.

Use the drain valve to lower the level to 100, 75, 50, 25 and 0%respectively as indicated on the graduated water column. Record the corresponding output readings. The percent error calculated from the results of above test shall not exceed the manufacturers stated limits.

g.

Transmitters with indicating scales, shall where necessary, have their indicating scales also calibrated during this tests.

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FLOAT TRANSMITTER AIR SUPPLY

100

DISPLACER INTERNAL 50

0

LEVEL GAUGE

FIG. - 16A

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ELECTRONIC m A

FLOAT TRANSMITTER

JB

TEST POINT

24 DC SUPPLY

100

DISPLACER INTERNAL 50

0

LEVEL GAUGE

FIG. - 16B

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LEVEL TRANSMITTER – EXTERNAL DISPLACER TYPE – PNEUMATIC / ELECTRONIC: a.

A temporary transparent flexible hose shall be connected to the level displacer chamber drain valve, and strapped to the displacer leg to display water level variation as shown in figure 17A & 17B page no. 31 & 32 respectively.

b.

The transmitter shall be calibrated in situ. The impulse lines to the vessel shall be closed the stand pipe vent open and the stand pipe impulse to the transmitter is open.

c.

The transmitter shall be calibrated using water as process liquid. If the transmitter does not have specific gravity compensation than the calibrated output must compensate for the disparity between the duty fluid specific gravity and the specific gravity of water (1.0). If the transmitter has a specific gravity adjustment, the adjustment shall be set at 1.0 for the duration of calibration. After the calibration has been completed, the specific gravity adjustment can be reset to the process specific gravity as specified on the Engineering Data Sheet.

d.

If the transmitter is pneumatic, then a 20 psig air supply shall be connected to the input port, and a standard pressure test gauge connected to the output port.

e.

If the transmitter is electronic, then the remote mounted receiver, either level indicator or level indicator controller, shall be energized at normal supply voltage, and a milliammeter connected in series with transmitter output. The meter shall be capable of reading a current variation of 4-20 mA DC.

f.

For calibration, water level variation shall be obtained by pouring in water through the open vent, and drawing of through the stand pipe drain valve.

g.

With the lock off valves open and the drain valve closed raise water level to 0% - 50% - 100% - 50% - 0% of instrument range as indicated by the water column. Record corresponding output readings. Raise water level to 110% and check against hysteresis. The percentage error calculated from the results of above test shall not exceed the manufacturers stated limits. Transmitters with indicating scale, shall where so necessary, have their indicating scale also calibrated during this test.

h.

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DISPLACER TYPE - EXTERNAL

PRESSURE GAUGE FLOT TRANSMITTER

TANK SHELL

100%

DISPLACER 50%

AIR SUPPLY

0%

LEVEL GAUGE

FIG. - 17A

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FLOAT OPERATED LEVEL SWITCH: a.

The float switch shall be calibrated in Situ. If the switch is mounted on a stand pipe, level variation shall be read off on the adjacent level gauge. If the level gauge has not been installed, then a temporary transparent flexible hose shall be connected to the level transmitter drain valve, and strapped to the displacer leg to display water level variation Refer figure 18 in page no. 34.

b.

If the switch is installed on a stand pipe, the stand pipe impulse lines shall be closed and the stand pipe vent open. The stand pipe impulse lines to the level switch shall be open, and the stand pipe and level switch drain valve closed.

c.

If the switch is electrical a continuity meter shall be connected across the terminals to check and verify the status of the contacts.

d.

Water shall now be poured through the vent valve, raising the water lever to a point where the switch status changes. The water shall then be drained slowly through the level switch drain valve to observe at what point the switch reverts to the original status as the level falls.

e.

If the switch is direct mounted, the upper impulse line shall be opened and the lower impulse line closed. a temporary liquid manometer shall be connected to the level switch drain valve as described in an above.

f.

Water shall be poured into the flexible hose. The water shall then be raised to a point where the switch status changes. The water shall then be drained slowly by cracking the flexible hose connection on the drain valve. Alternatively, a needle valve can be tied in to the flexible hose to drain the water. The level at which the level switch reverts to the original status shall be noted. All water used for checking the level switch shall be drained and lines flown through with air on completion of tests.

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LEVEL SWITCH

A

TANK SHELL

100

FLOATS 50

0

LEVEL GAUGE

FIGURE 18

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6.17

6.18

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SOLENOID VALVES: a.

A functional test shall be applied to each valve, on air or gas service by connecting an air supply to the inlet port and energizing the coil with the correct electrical power supply.

b.

Hydraulic pressure source shall be used where the air pressure required will exceed that laid down by site safety requirements.

c.

The test pressure shall equal the maximum differential pressure for which the valve is rated by manufacturer. Where this information is not available, the valve shall be tested with an air pressure equal to 110% of the working pressure at which the valve will be used.

d.

For valves on liquid service, the test procedure shall be same except that water supply shall be used to simulate liquid service.

e.

Application or removal of power depending on operational mode shall close the valve for 2 way valves, or close the inlet port and divert outlet port to vent port for 3 way valves. Three way valves shall be checked for air leakage at vent which should be zero when inlet is open to outlet with outlet plugged.

f.

Where a manual reset level is provided the reset action shall be checked.

CONTROL VALVES: a.

Check that, where specified, the lubricator is fitted and charged with the correct lubricant.

b.

If the valve is fitted with a hand wheel, then the hand wheel shall be disengaged during calibration.

c.

With no pneumatic signals applied to the actuator, the valve stem travel plate resting position with respect to valve stem travel scale shall be checked. This stem position shall then be checked against engineering data sheet to ensure conformance to specification.

d.

Valve without positioners (Ref figure 20A page no39). i)If the valve is not fitted with a positioner a regulated air supply adjustable from 0-20 psig shall be connected to actuator signal port. ii)

The signal input shall now be applied incrementally through 0% to 100% and to 0% of signal input range as detailed on the calibration sheet.

iii)

If required, the valve spring zero can be adjusted to obtain the correct input signal/valve stem travel relationship as detailed on engineering data sheet.

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e.

f.

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Valves fitted with positioners (Ref. figure 20B page no. 38). i)

A regulated air supply shall be connected to the positioner supply port. The supply pressure shall be set at the pressure specified in the valve actuator data plate.

ii)

Calibration equipment as shown in the figure "20B" shall be connected to the positioner input signal port.

iii)

The input signal shall be now applied incrementally through 0% - 100% 0% of signal input range as detailed on the calibration sheet.

iv)

The valve shall take up the same position in the upward and downward direction with the limits of +5% of the vale stroke reading in the dial indicator. The hysteresis, if present shall be measured with a micrometer dial indicator (clock gauge).

v)

If required the positioner span and zero settings shall be adjusted to obtain the correct input signal/valve stem travel relationship as detailed in engineering data sheet.

Fail Safe Action The input signal shall be applied to drive the Valve stem to 50% travel. The air supply shall then be turned off and the fail safe action observed and checked against the engineering data sheet specification, i.e. fail close or open or stay-put if a lock in relay fitted.

g.

Valve stem travel limit switches If limit switches are fitted, then switch operation shall be checked using continuity meter when the valve stem calibration is in progress. Switch status related to stem position shall be included on the instrument calibration sheet (Control Valves).

h.

Valve stem travel transmitter If the valve is fitted with a valve stem transmitter then calibration shall be as follows: i)If transmitter is pneumatic, then a separated regulated air supply set 20 psig shall be connected to the input port and a standard pressure gauge to the output. Simulate analogue input signals over the full travel range of control valve type under test during calibration. The generated analogue signal valve shall be usually displayed by using standard equipment/ The input and impulse signal shall be applied incrementally through 0% - 100% - 0% as detailed on the calibration sheet.

ii)

When the input signal is incrementally applied, comparison shall be made between the signal input as displayed by the standard test equipment

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monitor, and the signal input as displayed by the transmitter under test. If necessary zero and span adjustments of the transmitter under test shall be altered to minimize or remove discrepancies between the calibration standard display and the indicator under test. i)

The control valve shall be stroked after installation.

j)

The input signal shall be applied to drive the valve stem to 50% of travel. The air supply shall then be turned off and fail safe action observed and checked against the engineering specification i.e. fail close or fail open or stay put if a lock in relay is fitted.

k)

If limit switches are fitted, then switch operation shall be checked using a continuity meter when the valve stem calibration is in progress. Switch status related to stem position shall be included on the instrument calibration sheet

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Pressure Gauge

Pneumatic Actuator Variable air supply

Control valve without positioner FIG. - 20A

Pressure Gauge

Positioner Std :Pressure Gauge Regulated Air Supply

Pneumatic Actuator Variable Air Supply

Control Valve FIG. - 20B TEST CIRCUIT FOR CALIBRATION OF CONTROL VALVE

OHCS-PROC-23 A 25-06-2010 Page 34 of 55

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6.19

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BALL VALVES: a. PRE-TEST CHECKS Before the ball valve is operated through full travel the following conditions shall apply. i)

Accumulator (if fitted) is charged with nitrogen to a pressure (as stated on vendors data sheets) via the inlet valve, and the inlet valve is then closed with the Nitrogen feed line disconnected. NB : It is essential that accumulator is charged with nitrogen before hydraulic system pressurized.

b.

ii)

The hydraulic oil system isolation valves are open. isolation valve to the accumulator (if fitted).

This includes the

iii)

Hydraulic system drain valves are closed including drain valve on accumulator (if fitted).

iv)

The actuator speed control throttle valves are fully open.

v)

The hydraulic actuator system is pressurized as per Vendors data sheet.

vi)

Air has been vented from the actuator system via the bleed valves.

vii)

Any hydraulic oil leaks are eradicated before testing begins.

viii)

Electrical power supply is connected to locally mounted mode control switch.

ix)

Electrical power supply is connected to the `remote control' terminals to energies or de-energies the `open and close solenoids'.

x)

Electrical power supply is connected to the shutdown over-ride solenoid. If two separate shutdown over-ride solenoids are fitted, then the two solenoids shall be powered from two separate electrical power supplies. BALL VALVE COMPONENT TESTS Where fitted, the following components shall be checked to ensure correct operation. I)

Transducer (4-20 mA input/output - 100% ball valve travel).

II)

Travel indicator (mechanical).

III)

Position transmitter (4-20 mA output).

IV)

Position transmitter (3.0 - 15.0 PSIG output).

V)

Limit switches.

vi)

Pressure gauges. The gauges can be observed during pressurization

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and depressurization to assess correct operation. Defective components shall be replaced. vii) c.

Mode switch operation (Auto - close - open)

BALL VALVE ACTUATION The following operations shall be checked out where applicable, and implemented as detailed. i)

Local manual actuation, using the mode switch selector in the open and closed positions.

ii)

Local manual control via accumulator with main hydraulic system isolated and feed line de-pressurized. Under these conditions the system shall be actuated to check that the valve can be operated through three full strokes.

iii)

Remote operation of the valve with the mode switch in the auto position. (open-Close action).

iv)

Remote operation of the valve via a 4-20 mA analogue command signal. (Open-Close action).

v)

Remote fail safe action with the mode switch in the `auto' position and the open and closed solenoids de-energized.

vi)

Operation of the override shut-down solenoid(s). The valve shall be moved under local or remote command action to the opposite position on the travel from that position designated as the fail-safe position. The shutdown solenoid(s) shall then be de-energized to check that the valve moves to the fail-safe position.

d. BALL VALVE FUNCTION CHECKS i)

When the pre-test checks listed above have been completed where applicable, the ball valve shall be traversed through full travel in both directions.

ii)

Motion of the ball valve spindle can actuate the components listed below. If fitted, these items should be function checked during dynamic operation of the ball valve.

Item A : Limit Switches Actuation of the limit switches to be checked as the ball valve reaches the extremity of spindle travel, where the switch changes state. Item B : Mechanical Travel Indicator. The indicator shall be observed through full travel to confirm that the ball valve

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spindle is moving through full traverse to the mechanical stop and that the actuator is driving the spindle in the correct direction as depicted by the travel indicator. Item C : Position Transmitter. The analogue output calibration shall be checked against linear increments of mechanical travel indicator. Intermediate points shall be checked and a transmitter calibration sheet record kept. Item D : Current to Hydraulic Power Transducer. A 4-20mA command signal shall actuate the ball valve through full travel as depicted by the mechanical travel indicator. Intermediate points shall e checked and transmitter calibration sheet record kept. Item E : Command Signal Transducer. The 4-20mA command signal input calibration shall be checked against corresponding valve travel and a transmitter calibration sheet record kept. e.

MODE SWITCH LOCAL CONTROL Local control shall be checked as follows: i)

Move mode selector switch to close position. Valve should close.

ii)

Move mode selector switch to open position. Valve should open.

iii)

Move the valve to the opposite position of the fail safe position. Switch off the electrical supply to the mode switch. Valves should move to the fail safe position. Switch back electrical supply on. iv) Move the valve to the opposite position of the fail safe position. Close the actuator hydraulic inlet isolation valve, and de-pressurize the inlet line. The valve should move to the fail-safe position. 6.20 CYLINDER VALVE: a. Connect the test instruments to provide an input signal 0 to 100% of range according to figure 21 shown in page no. 42. b. Calibrate the device using Manufacturer's published data and method. c. Check the limit switches for proper action if required. d. Cylinder operated valve shall be calibrated for 0% and 100% of range only. e. After calibration, valves shall be protected from damage, moisture and dirt.

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Pressure Gauge

Continuity Tester

FIG - 21

TEST CIRCUIT FOR CALIBRATION OF CYLINDRICAL VALVE

6.21

SAFETY RELIEF VALVE:

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a.

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Inspection, Testing and Handling Equipment The test fluid, air or gas should be filtered to ensure that no particles of foreign matter pass through into the valve. The test equipment itself should be constructed of such material that there is no possibility of rust or scale forming, which could be blown through into the valve with resultant damage to the seat surfaces or preventing a tight shutoff. Before testing the test equipment shall be blown out with high pressure air to remove any dust or particles which may have accumulated inside. The inlet side of the valve itself shall be very carefully cleaned to ensure that there is no dirt, dust or loose particles adhering to the inside of the nozzle or the underside of the disc. Only new gaskets and/or rings of appropriate size and rating shall be used when pressure testing relief valves.

Accurate Gauge Standard Gauge : Class 0.5 PSV Inst Air

N2 Max Press : 120 barg

Accurate Gauge

Air Chamber Manifold V/v

Vent

Max Press : 8 barg

Water Tank Max Press : 1130 barg

Air Driven Fluid P/p

* Test chamber to be hydro tested at 1.5 times the operating pressure.



All relief valves shall be mechanically protected on both inlet and outlet flanges faces and clearly identifies and tagged with project system numbering.

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b.

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

Before testing, they shall be store in the upright position on pallets or shelved in clean dry warehouse.



Before popping test, clarify whether liquid service or Air/Gas service for safety valve.



Carry out the valve lift test. The valve shall be lifted three (3) times at the design set pressure.

Setting and Testing of Relief Valves. i.

Cold Setting of Valves.

A.

Valves will normally be set in cold condition on the test bench. The valve will be set by gradual application of hydraulic pressure and adjusting the setting mechanism so that the valve starts to lift at its registered `cold set pressure'.

B.

The valve will normally be first set by an applied hydraulic pressure. It will subsequently be lifted three times by the further application of hydraulic pressure in the case of valves on liquid duty and by air/nitrogen pressure in the case of valves on vapor duty.

C.

Valve operation above 70 barg to be tested for lift using hydraulic mediums only. Each test should meet the following criteria for reset pressure. Cold set pressure. Valve Cold set pressure. Valve seat 1.25” dia or less or “H” seat exceeding 1.25” dia or orifice and smaller “J” orifice and smaller

over 6.9 barg

10%

10%

4.4 - 4.8 barg

8%

5%

0.69 - 4.1 barg

5%

3%

0.14 barg

0.07 barg

< 0.69 barg

ii)

Leak Testing of valves After setting of lifting or reset pressures, the valve seat shall be tested for tightness by applying nitrogen gas to the inlet side of the valves. The applied

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pressure of nitrogen shall be 90% of cold set pressure. The leakage rate is measured by a bubble bath fixed to the outlet side of the valve, shall not exceed the rate listed below. The bubble count shall not start until the pressure has been applied for 2 minutes and the duration of count shall be over a 2 minute period for valves up to 4 inches inlet; for valves above 4 inches inlet count shall be over a 5 minutes period. If a valve has a cold set pressure greater than 68.96 barg it is preferable to leak test with gas over water. The maximum leakage rate shall be;( refer API527 3th EDIT – bubble test ). Below 6.9 Mpa

Bubble/Minute

G orifice and large 20 F orifice and smaller Above 6.9 Mpa

40 Bubble/Minute

G orifice and large 30 F orifice and smaller C.

60

Valve subject to back pressure - Body test. Valves subject to back pressure during the normal course of operation will have a hydraulic test equivalent to 1.5 times the maximum back pressure that the valve will normally operate under, applied to the outlet side of the valve.

D.

Valves with balancing or sealing bellows: Any bellows showing signs of deformation will be rejected. After all other tests have been carried out the bellows will be tested by applying 10 psig air/nitrogen (unless otherwise specified) in the outlet branches of the valve with a soap solution over the bonnet air vent. Prior to the test the vent will have been proved clear by rodding with wire. No leakage will be permitted

6.22

RELAY, BOOSTER & CONVERTER: 1.

Make connections as shown figure 22A and 22B on page no. 47 to provide input and output indication of 0 and 100% of range

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2.

Calibration shall fix accuracy values of 0%, 50% and 100% of range.

3.

Set direct or reverse control action as specified for specification loops.

PRESSURE GAUGE

OHCS-PROC-23 A 25-06-2010 Page 42 of 55

STD: PRESSURE GUAGE

RELAY OR BOOSTER CALIBRATING AIR SUPPLY

REGULATED AIR SUPLY FIG. - 22A

MILLI-AMMETER

STD: PRESSURE GUAGE mA E/P CONVERTER VARIABLE CURRENT SOURCE

REGULATED AIR SUPLY FIG. - 22B

TEST CIRCUIT FOR CALIBRATION OF RELAY OR BOOSTER & CONVERTER

6.23

PNEUMATIC CONTROL CIRCUIT PRESSURE TEST: a.

Blow down air line clean.

b.

Disconnect air consuming pilots, if any from the section of tubing to be tested.

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c.

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Connect the test assembly as shown in figure23 in page no. 47.

d.

Operate the test assembly for a 3-15 psig system.

e.

Open the valve and adjust the pressure regulator until the red pointer reads 15 psi.

f.

Adjust precision relay, till black pointer reads 15 psi.

g.

Close Valve. A drop in pressure as indicated by the black pointer will indicate a tubing leak.

h.

Permissible leak tolerance. Pressure shall not fall by more than 1 psig in 10 minutes

PRESSURE REGULATOR VALVE TO TEST LINE AIR SUPPLY INPUT AIR SUPPLY CONTROLLER OF RELAY

RED POINTER

BLACK POINTER DUPLEX PRESSURE GAUGE

Fig. 23

6.24

ELECTRONIC RECORDERS: a.

Ascertain that the pen properly inks and writes on the chart.

b.

Install ink supply if required.

c.

Make connections as shown in Figure 24A, 24B and 24C on page 48 to provide an input signal 0 to 100% of range.

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d.

Install the chart if required and check scale range to match specification.

e.

Calibration check shall fix accuracy values at 0%, 50% and 100% of range.

f.

6.25

OHCS-PROC-23 A 25-06-2010

Calibrate the device using Manufacturer's published data and method.

PNEUMATIC RECORDER: a.

Ascertain that the pen properly inks and writes on the chart.

b.

Install ink supply if required. [Must to provide record on the chart].

c.

Make connections as shown in Figure 25 to provide an input signal 0 to 100% of range shown in page no. 49.

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d.

Install the chart if required and check scale range to match specification.

e.

Calibration check shall fix accuracy values of 0%, 50% and 80% of range.

f.

Calibrate and device using manufacturers published data method.

PRESSURE GAUGE

RECORDER

REGULATED AIR SUPPLY

CALIBRATING AIR SUPPLY

COMPARATOR

FIG. 25

TEST CIRCUIT FOR CALIBRATION OF PNEUMATIC RECORDER

6.26

PRESSURE & TEMPERATURE RECORDERS: a.

GENERAL Calibration of zero span and linearity is controlled by the adjustment of the interconnecting linkage. In a typical instrument, the mechanical motion of a measuring device transmitted through the linkage, to a pen or pointer. Instruments having multiple pens, will contain separate linkages for each system. Although the mechanical configuration of the linkage, may differ in appearance for Instruments from different manufacturers, the basic linkage function of transferring the mechanical motion from each device to another,

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remains the same. b. CALIBRATION CHECK – PRESSURE RECORDERS

c.

i.

Connect the recorder to the Calibration setup as shown in Figure 26A or 26B in page 52 as applicable.

ii.

With zero pressure applied to the recorder "pressure input", adjust the pen to record zero on the chart. Adjust zero by adjusting the set screw, (Figure 26D), as necessary.

iii.

Apply 100% pressure (full range) and verify that the pen moves across the scale to the 100% pressure indication. Adjust span with the Range screw (Figure 26D), as necessary.

iv.

Apply 50% of the pressure range and verify that pen indicates 50% pressure on the chart. If it does read 50% reading, repeat step (2) and (3) here above.

v.

Typical points of Calibration for initial check on the recorder to ascertain its usability are made at 0%, 50% and 100% of the operating span. For example a recorder with range of 0-500 psig would have input check at 0, 250 and 500 psig. Three point calibration check is a minimum requirement.

vi.

Subsequently, the Recorder shall be subjected to Calibration checks at 25% and 75% of the Full Range, prior to releasing the instrument for use in the field.

vii.

Some times the instrument may be out of calibration to reach an acceptable level after five point Calibration check at 0%, 25%, 50%, 75%, 100% . In this case even the above checks are repeated until the instrument comes within the specified tolerance of the true Calibration span (i.e. Five point Calibration).

viii. The output versus input readings which will be noted during calibration should be written down and finally filled up in the Calibration sheet provided for the record purpose. CALIBRATION CHECK – TEMPERATURE RECORDERS i.

Connect the temperature recorder to the Calibration set-up as shown in Figure.26C in page 53.

ii.

Adjust the pen to read ambient Temperature on the chart by adjusting the zero adjust screw.

iii.

Full temperature range between maximum of the unit and the ambient is required to be checked and adjusted until the instrument comes within specified tolerance of the true calibration span (e.g. 4 point calibration).

iv.

The output versus input readings which will be noted during Calibration

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should be written down and finally filled up in the Calibration sheet provided for the record purpose.

INSTRUMENT TO BE CALIBRATED TEST GAUGE

BLOCK VALVE

REGULATOR

BLOCK VALVE VENT VALVE SUPPLY

LOW PRESSURE RECORDER FIG. - 26A LOW PRESSURE RECORDER

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TESTING & CALIBRATION PROCEDURES FOR MODIFICATION AND HOOK-UP WORKS AT OFFSHORE Instrument to be calibrated

Block valve

DEAD WEIGHT TESTER FIG. - 26B HIGH PRESSURE RECORDER

STA NDA RD THERMOMETER

TEMPERATURE RECORDER

WATER OR SILICON OIL

TEMPERATURE BULB HEA T SOURCE

TEMPERATURE BATH FIG. - 26C

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RANGE ARM LOCK SCREW STATIC PRESSURE ELEMENT

PEN MOUNT PEN SHAFT LINK

RANGE ARM 90

CLAMPLOCK SCREW

PEN ZERO ADJUST SCREW LINK SCREWS DRIVE LINK

TUBING CONNECTION

THUMB NUT

THUMP NUT

LOCK SCREW LEVER ARM RECORDER CHART

FIG. - 26D

STATIC PRESSURE PEN LINKAGE

6.27

CHECK OF ORIFICE PLATE a) Confirm orifice plate is not damaged or shows signs of corrosion. b) Check upstream orifice marking contain the following.     

The word “upstream” The tag number The ANSI flange class, followed y “RF” The nominal size in DN (in mm) The measured orifice diameter (in mm)

c) Check difference between any two measurements of the plate thickness is within 0.00DN (in mm) d) Check that the surface finish of the throat and plate are free from visible scratches and indentations. e) Check throat edges are sharp and free from burrs. Check there is no light reflected from the corners of the square edge plates. f) Confirm that location and size of the bleed hole / vent hole (where applicable) confirms to requirements for orifice type. g) Measure and confirm diameter of orifice(d) at upstream flange face on the horizontal, 80’ and 120’ axis.

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h) Record the calibration test result on check sheet form. 6.28

FLOW METER(ULTRASONIC, TURBINE METER, THERMAL TYPE) a) In case of ultrasonic, turbine meter and thermal type, basically it does not need any calibration test at site but function test at site but function test and visual check only. These meters will be checked for range using the HART communicator against. b) Manufacturer’s pre dispatch calibration report shall be made available. c) Record the calibration test result on check sheet form.

6.29

FIRE & GAS SYSTEM a) The fire & gas detection system generally compromises of strategically placed field sensors and a centrally located alarm / display panel and control system. b) The F&G control system is also linked to the F&G protection system which compromises of fire water pumps, the sprinkler system, fire hydrants and the foam monitor. c) The sensors for the F&G detection system can be tested using any one of the following.     

Gas ampoules or cylinders containing calibration gas samples. Smoke canisters UV / infrared radiation emitters Heat source Source of flame

Where voting logic is involved, then each combination of the activities inputs shall be tested and all resultant outputs checked and verified. d) The fusible loop shall be checked by dropping the line pressure and verifying the actuation of the control valve. e) Similarly, the sprinkler system can be checked and verified by simulating the alarm condition and ensuring that the solenoid of the line control valve gets operating signal. f) The alarm should be energized and the “TEST” , “ “ACCEPT” and “RESET” buttons operated to ensure that the display windows are functional and that the alarm sequence is operational. NOTE:- Prior to testing the F&G system ensure that all personnel working on the same, to avoid panic due to frequent sounding off of the alarm. g) The complete F & G system including the ESD checked and verified against the F&G cause and effect diagram.